Of the rotating cast of characters in the Russia saga, Congressman Dana Rohrabacher’s role is perhaps the most curious. Though he has no formal ties to Donald Trump’s campaign, the California Republican—whose consistent advocacy for warmer relations with Moscow reportedly earned him a Kremlin code name—has intersected with Trumpworld at critical points. Rohrabacher’s reputation as a Russophile has never been a secret; the congressman has spent decades pushing for improved relations between the U.S. and Russia, and his support for Vladimir Putin reached such a level that, in 2012, the F.B.I. warned the lawmaker that Russian spies were trying to recruit him. But as F.B.I. investigators and lawmakers alike seek to determine the breadth of Russia’s election interference, Rohrabacher’s Kremlin ties and repeated cameos have reportedly taken on a newfound significance, drawing scrutiny from Special Counsel Robert Mueller and congressional investigators amid efforts by his Republican colleagues to curtail his authority.

Like Sergey Kislyak, Rohrabacher has always hovered around the periphery of the Trump-Russia story. In April 2016, a Russian official provided Rohrabacher with a memo containing the same accusations against Democratic donors and the Hillary Clinton campaign that Natalia Veselnitskaya would detail to Donald Trump Jr. during their now-infamous meeting at Trump Tower months later. The same month Trump won the presidency, Rohrabacher met withMichael Flynn, Trump’s former national security adviser, and his son, Michael Flynn Jr., both of whom have emerged as key figures in the Russia probe and are expected to be indicted by Mueller’s team. In February, Rohrabacher dined privately with Alexander Torshin, the deputy governor of the Russian central bank who reportedly sought to set up a “backdoor” between Russian President Vladimir Putin and Trump. And this past August, Rohrabacher traveled to London to meet with WikiLeaks founder Julian Assange, whom U.S. investigators believe acted as an intermediary for the Kremlin to release thousands of stolen e-mails damaging to the Clinton campaign.

Rohrabacher dismissed the suggestion that any of these encounters were questionable, citing his chairmanship of the Foreign Affairs subcommittee on Europe, Eurasia, and Emerging Threats, which oversees Russia policy, as the reason for them. “I feel like I’m in good shape politically,” Rohrabacher told the Times. “My constituents couldn’t care less about this. They are not concerned about Russia. They are concerned about the taxes on their home. They are concerned about illegal immigrants coming into their neighborhood and raping people.”

According to The New York Times, Mueller is seeking to interview the congressman about his meeting with Flynn and Flynn Jr., while both the F.B.I. and the Senate Intelligence Committee want to hear Rohrabacher’s account of the meeting with Assange. Meanwhile, Rohrabacher’s fellow G.O.P. lawmakers have moved to limit his power. According to the Times,Ed Royce, the chairman of the House Foreign Affairs Committee, ousted Rohrabacher’s top aide, Paul Behrends, in July amid questions about his ties to Russian lobbyists, and exerted greater oversight over Rohrabacher’s actions as chairman of the subcommittee. And, back in California, Rohrabacher’s upcoming re-election bid could be complicated by challenges on both flanks.